Search results for "district"
showing 10 items of 202 documents
District metered area design through multicriteria and multiobjective optimization
2022
[EN] The design of district metered areas (DMA) in potable water supply systems is of paramount importance for water utilities to properly manage their systems. Concomitant to their main objective, namely, to deliver quality water to consumers, the benefits include leakage reduction and prompt reaction in cases of natural or malicious contamination events. Given the structure of a water distribution network (WDN), graph theory is the basis for DMA design, and clustering algorithms can be applied to perform the partitioning. However, such sectorization entails a number of network modifications (installing cut-off valves and metering and control devices) involving costs and operation changes,…
Solutions for districting problems with chance-constrained balancing requirements
2021
Abstract In this paper, a districting problem with stochastic demands is investigated. The goal is to divide a geographic area into p contiguous districts such that, with some given probability, the districts are balanced with respect to some given lower and upper thresholds. The problem is cast as a p -median problem with contiguity constraints that is further enhanced with chance-constrained balancing requirements. The total assignment cost of the territorial units to the representatives of the corresponding districts is used as a surrogate compactness measure to be optimized. Due to the tantalizing purpose of deriving a deterministic equivalent for the problem, a two-phase heuristic is d…
The Influence of Business Ecosystems on Innovation-Based Industries: A Research on the Mechanical Sector in Italy
2018
The business ecosystem perspective can be considered as a more advanced point of view for interpreting the development of local economic systems, if compared to more traditional concepts such as clusters, industrial districts, local or regional systems, and local networks. The business ecosystem perspective allows to better highlight the adaptive and evolutionary nature of local systems in front of the changing external environment and dynamics on national and international markets. The aim of the research was to analyze the key characteristics of firms belonging to a local business ecosystem specialized on an innovation-driven industry – the mechanical sector – in order to verify which kin…
Landscape and firewood procurement at the prehistoric and protohistoric site of Ses Païsses (island of Mallorca, Western Mediterranean)
2017
Abstract In this article we present the anthracological study of the settlement of Ses Paisses, located in north-eastern Mallorca (Balearic Islands, Western Mediterranean). A total of 25 charcoal samples have been analysed, corresponding to both concentrated (hearth and oven content) and dispersed charcoal fragments. The samples come from four different buildings of the settlement, each one showing different phases of occupation. The site presents a long sequence of occupation (from c.1212-1005 cal BC to the 1st century cal AD), expanding from the last centuries of the Bronze Age (Naviform), through the Early (Talayotic) and Late (Post-Talayotic) Iron Age up to the beginning of Roman occupa…
The Arrival of Steppe and Iranian Related Ancestry in the Islands of the Western Mediterranean
2019
A series of studies have documented how Steppe pastoralist-related ancestry reached central Europe by at least 2500 BCE, while Iranian farmer-related ancestry was present in Aegean Europe by at least 1900 BCE. However, the spread of these ancestries into the western Mediterranean where they have contributed to many populations living today remains poorly understood. We generated genome-wide ancient DNA from the Balearic Islands, Sicily, and Sardinia, increasing the number of individuals with reported data from these islands from 3 to 52. We obtained data from the oldest skeleton excavated from the Balearic islands (dating to ∼2400 BCE), and show that this individual had substantial Steppe p…
New insights into the daily and symbolic use of plants during initial occupations of Formentera (Balearic Islands, Spain)
2021
The island of Formentera, with its small extension and flat orography, was settled relatively late in Mediterranean prehistory between the third and second millennium BC. The sites presented in thi...
Testing Taxonomic and Biogeographical Relationships in a Narrow Mediterranean Endemic Complex (Hippocrepis balearica) using RAPD Markers
2002
Analyses of RAPD profiles from 17 populations of the Hippocrepis balearica complex revealed a highly structured geographic pattern, not only among continental–insular areas but also within the eastern Balearic islands. In marked contrast to previous morphometric results, a clear separation between continental and insular samples was found, and intermediates between H. balearica and H. valentina samples were not detected. Molecular data indicated that western and eastern Balearic populations of the complex (H. grosii and H. balearica) were more closely related to each other than to continental populations (H. valentina). Multivariate analyses of the RAPD data clearly indicated that the simil…
The Balearic toad (Bufo viridis balearicus (BOETTGER, 1881)), human bronze age culture, and Mediterranean biogeography
1981
Abstract Microcomplement fixation analysis of albumin relationship shows that the Balearic green toad (Bufo viridis balearicus) is not an original, autochthonous member of the basically Miocene fauna of these western Mediterranean islands, but a quite recent newcomer. The plasma protein pattern clearly points to its close populational relationship to the Tyrrhenian islands' conspecifics. The male and female release vocalization shows the same, and this is in accordance with the external morphology too. There has been no possibility for toads to reach the Balearic Islands in Pleistocene or Holocene via land bridges, nor are they candidates for any sea drifting. Anthropogenic introduction mu…
Typification of the Linnaean name Centaurea seridis (Asteraceae)
2014
The genus Centaurea Linnaeus (1753: 909) (Asteraceae) comprises a large number of taxa mainly occurring in the Mediterranean region and southwest Asia (Susanna & Garcia-Jacas 2007). Centaurea seridis Linnaeus (1753: 915) is distributed from south Europe (Spain incl. Balearic Islands, Italy incl. Sicily, France, Albania and Greece) to northwest Africa (Algeria, Morocco and Tunisia). From a nomenclatural standpoint, Centaurea seridis has not been typified (Jarvis 2007: 402). This paper proposes the designation of a lectotype for this Linnaean name, based on the analysis of the protologue and original material.
Nuclear and chloroplast DNA variation in Cephalaria squamiflora (Dipsacaceae), a disjunct Mediterranean species
2009
Cephalaria squamiflora is a chamaephyte restricted to rupicolous habitats in islands of the Western (Balearic Islands, Sardinia) and Eastern Mediterranean (Crete and few Aegean islands). Four narrowly distributed races (subspp. squamiflora, mediterranea, ebusitana, balearica) have been described to encompass the morphological variation within the species. We have used nuclear ribosomal ITS and cpDNA sequences to assess how the patterns of molecular differentiation are related to taxonomic and geographic boundaries. Extensive intragenomic ITS variation was detected in samples from all territories, the average sequence divergence among cloned ribotypes was 1.339%. The parsimony network of clo…